It's not so much how much you eat but what you eat. I ate a bunch of chips yesterday and too much salt and I gained 2 lbs. I am sure that it is mostly water and I can probably lose it in a day on 1200 cals, but I have to eliminate chips from my diet.
It looks like you are starting to yo-yo. Be careful not to get stuck at the same weight.
Those one day weight reductions that you are getting on 1200 calories and 90 minutes of exercise are impressive but the real test will be if you can meet your long term weight loss goals.
Your rotation doesn't seem to fit any pattern now. Neither Katahn's or your own modifications?
I am anxious to see how those second week modifications work out for you. Hopefully it will not lower your metabolism.
Lost 3 lbs. on 1200 cals and 90 mins exercise.